docs: def find_port(addr, user):
      """Find local port in existing tunnels"""
      import pwd
      home = pwd.getpwuid(os.getuid()).pw_dir
      for name in os.listdir('%s/.ssh/' % home):
          if name.startswith('unixpipe_%s@%s_' % (user, addr,)):
              return int(name.split('_')[2])